Table 1.

Algorithm for cohort identification from the SEER-Medicare database.

Criteria	Number
Diagnosed with head and neck cancer as only or first cancer	95,264
Diagnosed 1999-2011	74,658
Pathologically confirmed	72,925
Not diagnosed by autopsy or death certificate	72,905
In Medicare for age only	56,617
Age at diagnosis ≥66 and ≤80 years	29,986
Enrolled in Medicare Part A and B 1 year prior and post diagnosis with no HMO	15,049
No missing stage; exclude Stage I/II larynx	9,949
Received either definitive or adjuvant radiation	5,418
Feeding tube users have both placement and removal dates after diagnosis, excluding patients with both dates prior to RT	4,699
Received either IMRT or 3DRT	4,570
SEER tumor stage localized or regional disease only	3,625
Exclude salivary gland	2,993